Hook and loop fasteners, such as those marketed under the trade mark VELCRO.TM. and equivalents, provide desirable ease and flexibility of fastening for garments, coverings and other items. However, for items which require laundering, hook and loop fasteners present added difficulties. The hook portions tend to adhere to other items in the laundry often causing damage or wear. The hook portions also tend to attract and become clogged with lint, eventually becoming unusable. Exposed hook fasteners also cause difficulty for handling and sorting items which can easily become hooked together, snagged or damaged.
To prevent these problems time must be spent joining the hook portion to the loop portion before laundering. This is time consuming and costly in a commercial laundry. Also, garments, such as diapers, are less easily cleaned in the fastened arrangement.
Various solutions to prevent the hook portions of fasteners from being exposed during laundering and handling have been proposed. In U.S. Pat. No. 4,537,591 issued to Fredrica V. Coates, a fastener is disclosed which includes a cover comprising an additional loop portion joined to the hook portion in face to face arrangement. The two pieces are stitched together so that they are biased towards each other and tend to self close when the hook portion is not in use. This system is not completely satisfactory since some pressure is required on the hook and loop elements for positive closure. Repeated washing tends to soften and change the shape of the fastener resulting in misalignment, and the possibility of the hook portion catching a portion of the garment instead of the loop cover portion.
In a previous U.S. Pat. No. 4,937,887 issued to the present inventor, a fastener is disclosed having a pocket of semi-rigid material containing a hook portion retractably secured by an elastic ligament. In use the hook portion is drawn from the pocket to expose the fastening surface. Once released, the hook portion is retracted back into the pocket where it is completely covered for laundering and handling.
This system has proven to have a number of problems. The use of semirigid material helps to maintain the desired shape of the pocket, but it is expensive to manufacture and insert on garments. The fastener of this prior art design also proved ineffective as the dimensions of the desired hook tab were changed. For some applications a larger Velcro area is needed for good adhesion. However as the Velcro dimension is changed, most noticeably with a wide pocket, the flat shape of the fastener is not always maintained. The pocket can open allowing the hook insert to become twisted or folded inside. If the shape of the pocket is not maintained, the hook insert does not reliably retract. The hook portion may become curled or folded and more difficult to fasten. Further, the insert of the prior art design does not always extend and retract along a straight path, and therefore does not reliably retract to protect the hook portion of the fastener. The prior art design does not provide any means to maintain the pocket shape, or to guide the direction the insert travels.
Additional problems with the prior art design were found when the insert is able to retract too far and become folded inside the pocket. The insert is then difficult to retrieve and sometimes becomes hooked to the fibers of the elastic causing damage. After repeated washing the elastic of the fastener relaxes permitting the hook portion to be withdrawn farther from the pocket. If the hook portion of the insert is completely withdrawn from the pocket, the projecting hooks at the edge of the hook portion catch on the open edge of the pocket and the insert resists retracting smoothly. The prior art design provides no means to control the length of travel of the insert into and out of the pocket.
While automatic retraction still seems to be an attractive way to protect the hook portion of the fastener during laundering, a more reliable fastener design is clearly needed, particularly for use with commercially laundered items such as in hospitals or other institutions.
It is an object of the present invention to provide a retractable hook and loop fastener which protects the hook portion from gathering lint or snagging other items during laundering or handling.